Steam-generating apparatus



Q (No Model.) V S. SMITH.

STEAM GENERATING APPARATUS. I No. 364,868. Patented June 14, 1887.

WlTNESSESI INVENTUR:

n. PETERS mwmhu hu. Washington. a a

NITED STATES PATENT OFFICE.

SIDNEY SMITH, or CAMBRIDGE, MASSACHUSETTS.

STEAM-GENERATING .AP-PARATUS.

SPECIFICATION forming part of Letters Patent No. 364,868, dated June14-, 1887.

Application filed April 7, 1887.

To all whom it may concern:

Be it known that I, SIDNEY SMITH, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Steam-Generati ng Apparatus, of which thefollowing is a specification.

My invention relates to boilers for generating steam, and particularlyto such boilers employing a locomotive fire-box in connection therewith,or to hog-nose boilers and common tubular or flue boilers.

My invention hasfor its object to so improve the feed-water-heatingcontrivances as to raise the temperature of the water supplied to theboiler to as near that of the steam generated therein as possible beforeadmitting the water to the boiler proper, so as to obviate the wear andtear of the boiler consequent upon unequal expansion and contraction,and at the same time avoid danger of explosion, &c., by keeping all ofthe parts of the shell of the boiler at a uniform temperature,preventing,

' also, disintegration, rupture, and breakage of both shell andstay-rods.

My invention also has for its object to so improve the construction instationary boilers of the heating chambers or contrivances in theirrelation to the boiler as to avoid unduly heating the same from the firechamber or box, or from the walls or casing of the same or'the boiler,above the low-water line of the latter, thus, in connection with theparticular provisions by which circulation of the water in the boiler issecured, and sediment or solid or glutinous matter calculated to formscale is frequently removed or blown off, effectually preventing any andall incrustation of the boiler, and removing scale from boilers in whichit has already formed from. any cause.

My invention also has for its objectimprovements incidental to theforegoing, having the attainment of substantially the same results inView.

.To the ends mentioned my invention consists in the improvements whichIwill now proceed to describe, so that others skilled in Serial No.233,989. (No model.)

part of this specification, Figure 1 represents a side elevation ofalocomotive-boiler and some of those parts immediately connectedtherewith (parts being shown as broken away) embodying my invention.Fig. 2 represents a diagram of the front end of. the boiler representedin Fig. 1, showing my improvements as applied thereto. Fig. 3 representsa side view of the invention as embodied in a stationary boiler, thecasing or framing being shown as in section Fig. 4 represents a verticalsectional View through the casing or framing on the line 1 l of Fig. 3.

Similar letters of reference indicate corresponding parts in all of thefigures.

In the drawings, reference being had to Figs. 1 and 2, a represents atubular locomotive-boiler of common construction; a, the eas ing or wallof the fire-box; c, the interior of the fire-box, and d the smoke-box.

The parts thus far described, as also the parts necessarily connectedtherewith for forming asteam-generating boiler, (not shown herein orparticularly illustrated or explained,) may he of common and well-knowncharacter, or such as are illustrated in the 'frontispiece plates of theCatechism of the Locomotive, by M. N. Forney, New York, the RailroadGazette, publishers, 1875, and as shownand described in the patentgranted to me November 27, 1883, No. 289,317, to which reference may behad. 6 represents the feed-water-supply pipe pro vided with acheck-valve, f, which feed'watersupply pipe extends out into anddiagonally upward in the smoke-box d, where it connects with thefeed-water-heating pipe g,which latter passes through one of the finesor tubes near one side of the boiler to the firebox, into which itissues, passing across to the opposite side of the boiler, where itenters a tube or flue higher up, returning to the smoke-box, into whichit extends, and by a connecting-pipe, 9, (see Fig. 2,) crosses to nearthe opposite side of boiler and outward at any convenient point is alarge pipe, h, forming a substantial receptacle or pocket for matter anda purpose to be presently explained. Said pipe his provided with asuitable blow-off cock, A pipe, j, extends out into the smoke-box fromthe boiler near the bottom thereof to and connects with thefecd-water-supply pipe 0, said first'ment tioned pipe being providedwith a suitable check-valve, Z, to prevent water forced into the boilerthrough the feed-water-supply pipe c from entering said boiler by theway of said pipcj, by which construction, when no water is being fed tothe boiler, a constant circulation of the water in the boiler will bekept up through the pipe j and g and the boiler.

In Figs. 8 and 4: I have represented a stationary boiler with myinvention applied thereto. In these latter views the parts similar tothose above described are indicated by similar letters of reference, andall of said similar parts are constructed and arranged to operate in asimilar manner. In carrying out the objects of my invention in itsapplication to this form of boiler, I make certain modifications in thestructure of its appurtenances, which I will now proceed to set forth.

llreprcsent sheets or plates of soapstone,

tile, or other suitable material built into the walls or casing,substantially as shown in my patent hereinbefore referred to, whichsheets project inwardly from the wall to near the sides of the boiler,the walls being at a little distance from the sides of the shell of theboiler.

m m represent sheets of asbestus, or sheets overheat the boiler-plates,as would hot ma sonry. An arched plate, in, of similar material, whichis a poor conductor of heat and is incombustible, serves as a cut-off tothe flames at the end of the boiler.

If desired, pipes or receptacles similar to pipe h may be provided at ornear the end opposite that at which said pipes are shown as attached tothe boiler, or at other points, which pipes may also be provided withblow off cocks similarto blow-off cock 1', said receptacles and pipesbeing comparatively large size, so as to effect by their operation apractical washing out of the boiler.

Before proceeding with a description of the operation of my invention itmay be well to still further explain the general principles upon whichit is based, as well as the difficulties heretofore experienced in theuse of contrivances to which it relates.

Steam, which is one of the most powerful mechanical agents known, is atthe same time in most respects one of the most manageable.

.were clean or free from crust.

Chief among the dangers attending its use are explosions, which itsometimes causes, and these results are in most instances unquestionablydue to the incrustation of the boilers. Another obj actionable effect ofincrustation is the fact that it necessitates an increased amount ofheat to generate steam, it being admitted that a boiler with a crustone-fourth of an inch thick requires sixty per cent. more fuel togencrate steam than would the same boiler if it If, therefore,incrustation can be avoided it will result in a great saving of fuel, aswell as a diminution ofdangers from explosion.

Incrnstation is produced by the accumulation upon the sides of theboiler of carbonates of lime, magnesia, oxide of iron, vegetable matter,and other substances in the water which are not convertiblcinto steam,and cannot be held in suspension and carried off by the steam, whichaccumulations on the sides of the boiler are burned thereon time aftertime in thin layers by the heat in the furnace until the interior of theboiler becomes heavily incrustcd. The substances in water which produceincrustation are precipitated at or neara temperature of 290 or less;and it has been demonstrated by tests that the residuum or substancesmentioned which produce incrustation will flow into eddies outside ofthe currents of circulating water in a boiler.

In carrying out my invention, I take ad van tage of the foregoing facts.First, by leading the feed-water-heating pi pcs through the dues of theboiler in the manner described, Iam enabled to introducewater to theboiler at or nearly at the same temperature as the steam generated,which i n the boilerof a high-pressure locomotive running from onehundred and twenty-five to one hundred and fifty pounds pressure is from330 to 350, and in alowpressure boiler from 220 to 300. This hightemperature of the water introduced to the boiler not only prevents thecontraction of the plates which cooler currents would produce, butadmits of the immediate precipitation of residuum and othercrust-forming substances, in the manner hereiubefore stated.

I have also ascertained that the pockets or receptacles formed by thepipes leading down from the bottom of the boiler near the point wherethe feed-water heaters are connected with the boiler and from the leg oflocomotiveboilers form favorable receptacles for these precipitatedsubstances, which receptacles I provide with blow-off cocks, which arefrequently operated and so constructed as to of-v fect a completewashing out ofthe receptacles and of the boiler as well.

To further facilitate precipitation of the substances mentioned, whichare superinduced by currents of water in the boiler, I connect thepipej, extending from the bottom of the boiler, with thefecd-water-hcating pipe r as stated, whereby, when the pump or injectorby which the water is forced from the tank to the boiler is stopped orthrown out of operation, a circulation is induced through the boiler andfrom it through said pipes. Practice demonstrates the fact thatcirculation, under the conditions mentioned, is constant through theboiler and pipes so long as there is any fire under the boiler, and thisconstant current of water sends all crust-forming sub stances in theirplastic or formative state into the receptacles mentioned, and which maybe provided in the bottom of the boiler.

The blow-off cocks connected with the residuum-receiving receptacles orpockets are designed to be frequently operated, as often as three timesa day, if necessary, in order to discharge the precipitated residuum andin effect wash out the boiler.

There bei mg no heat of consequence from the fire applied to the boilerabove the low-water line, there is no means or'agency for burning ordrying the crust substances on the interior of the boiler; and the.residuum receiving pockets or receptacles being below theheating-point, such crust'forming substances as are precipitated thereinare free from all liability of being burned onto the interior of theboiler, as they must be in order to form a crust.

It is well known that a line or ridge of scale or coating is frequentlyfound on the inside of boilers at or near the waterlevel. In the commonsetting the casing or walls come in contact with the shell at thispoint, and this ridge is caused by the heat from the walls or casingsburning the scum floating on the surface of the water onto the shell. Inmy method the incasing-walls are kept away from the shell and theburning on of scum from the radiated heat entirely avoided; and,furthermore, as practical tests have demonstrated,

'by my described improvements, incrustation may be removed from boilersin which it has already formed and become fixed to the internalsurfaces.

The use of my improvements may produce chemical or physical changes aswell as electric currents not herein enumerated in the attainment of theresults specified; but further knowledge of matters of this nature isnot necessary to an understanding of my invention.

I am well aware that handholes in the head of the boiler areiu commonuse, and that blow'offs are now employed in the heads of boilers as wellas in the'sides of the waterlegs, which blow-offs are designed to beused at the close of 'each week, or at longer intervals, in blowing offthe boiler, in order to permit the -free residuum to be scraped outthrough the hand-holes, the covers of which are removed. I therefore donot claim the use of these devices as constituting my invention, butconfine the same to the construction stantially as'and for the purposestated.

2. The combination, with a boiler, of a feedwatenheating pipe connectedwith the boiler at the lower portion of the head by a connection havinga check-valve whichcloses toward the boiler, said feed-pipe runningthrough the tubes or fines of the boiler and entering the same at orbelow the water-line, for the purposes set forth.

3. The combination, with a boiler, of afeedwatcr-heating pipe connectedwith the boiler at the lower portion of the head by a pipe having acheck-valve which closes toward the boiler, the feed-pipe entering andrunning through a fine rising and crossing at the opposite end oft-heboiler and entering a flue at the side opposite to that through whichitfirst passed, returning to the first-mentioned end through thelast-mentioned flue and entering the boiler at or below the water-line,as set forth.

4. The combination, with a boiler, of a feedwater-heating pipe providedwith the checkvalve f, which opens toward the boiler, said pipeconnected with the boiler at the lower portion of the head and runningthrough the tubes or fines of the boiler and entering the same at orbelow the water-line, and the connecting-pipe 9', provided with acheclovalve closing toward the boiler, as set forth.

5. The combination, with a boiler, ofafeedwater-heating pipe providedwith the checkvalve f, opening toward the boiler, said pipe connectedwith the boiler at the lower portion of the head and running through thetubes or fines of the boiler and entering the same at or below thewater-line, the connecting-pipe j, provided with a check-valve closingtoward the boiler, with a pocket or pipe at the bottom of SIDNEY SMITH.

provided with a blow-off cock, as

Witnesses:

A. D. HARRISON, H. BROWN.

